I've been tracking this coin for a while now, and the price just keeps going higher. Of all the silver Kennedy half's, this has the lowest mintage(395,443) by quite some way. I've been tracking the NGC PF70 coins, and the price has almost tripled in under 12 months. Last March these coins were selling for $50 a piece, on eBay, and now they are selling upwards of $140. I managed to snag a few, but wish I'd snapped up a ton more. Also the availability of this coin has dropped too, there are very few left on eBay for sale.
I've no idea where this coin will finish up at, but I see it breaking $200 by the end of the year. I recon the collector base on the Kennedy's far exceeds the collect base for Silver Eagles. One to keep an eye on, especially if you can find one under $100.